How to Contribute to OpenStreetMap and Grow the Open Geodata Set

Hundreds of delegates from government, civil society, and business gathered in Brasilia recently for the first [Open Government Partnership meetings](http://www.opengovpartnership.org/Brasilia2012) since the inception of this initiative. Transparency, accountability, and open data as fundamental building blocks of a new, open form of government were the main issues debated. With the advent of these meetings, we took the opportunity to expand an open data set by adding street names to [OpenStreetMap](http://www.openstreetmap.org/).

![](http://farm8.staticflickr.com/7091/7104558195_47e9329228.jpg)

Getting ready to survey the Cruzeiro neighborhood in Brasilia.

OpenStreetMap, sometimes dubbed the “Wikipedia of maps,” is an open geospatial database. Anyone can go to [openstreetmap.org](http://www.openstreetmap.org/), create an account, and add to the world map. The accessibility of this form of contribution, paired with the openness of its common data repository, holds a powerful promise of commoditized geographic data.

As this data repository evolves, along with corresponding tools, many more people gain access to geospatial analysis and publishing — which previously was limited to a select few.

When Steve Coast founded OpenStreetMap in 2004, the proposition to go out and crowdsource a map of the world must have sounded ludicrous to most. After [pivotal growth in 2008](http://vimeo.com/2598878) and the widely publicized [rallying around mapping Haiti in 2010](http://www.youtube.com/watch?v=e89Tqr75mMw), the OpenStreetMap community has proven how incredibly powerful a free-floating network of contributors can be. There are more than 500,000 OpenStreetMap contributors today. About 3 percent (that’s still a whopping 15,000 people) contribute a majority of the data, with roughly 1,300 contributors joining each week. Around the time when [Foursquare switched to OpenStreetMap](http://blog.foursquare.com/2012/02/29/foursquare-is-joining-the-openstreetmap-movement-say-hi-to-pretty-new-maps/) and [Apple began using OpenStreetMap data in iPhoto](http://mapbox.com/blog/apple-and-their-maps/), new contributors [jumped to about 2,300 per month](http://mapbox.com/blog/osm-contributors-surge/).

As the [OpenGovernment Partnership meetings](http://www.opengovpartnership.org/Brasilia2012) took place, we wanted to show people how easy it is to contribute to OpenStreetMap. So two days before the meetings kicked off, we invited attendees to join us for a mapping party, where [we walked and drove around neighborhoods](http://mapbox.com/blog/surveying-brasilia/) surveying street names and points of interest. This is just one technique for contributing to OpenStreetMap, one that is quite simple and fun.

Here’s a rundown of the most common ways people add data to OpenStreetMap.

Getting started

It takes two minutes to get started with contributing to OpenStreetMap. First, create a user account on [openstreetmap.org](http://openstreetmap.org). You can then immediately zoom to your neighborhood, hit the edit button, and get to work. We recommend that you also download the [JOSM editor](http://josm.openstreetmap.de/), which is needed for more in-depth editing.

Once you start JOSM, you can download an area of OpenStreetMap data, edit it, and then upload it. Whatever you do, it’s crucial to add a descriptive commit message when uploading — this is very helpful for other contributors to out figure the intent and context of an edit. Common first edits are adding street names to unnamed roads, fixing typos, and adding points of interest like a hospital or a gas station. Keep in mind that any information you add to OpenStreetMap must be observed fact or taken from data in the public domain — so, for instance, copying street names from Google is a big no-no.

Satellite tracing and GPS data

JOSM allows for quick tracing of satellite images. You can simply turn on a satellite layer and start drawing the outlines of features that can be found there such as streets, building foot prints, rivers, and forests. Using satellite imagery is a great way to create coverage fast. We’ve [blogged before about how to do this](http://mapbox.com/blog/satellite-tracing-osm/). Here’s a look at our progress tracing Brasilia in preparation for the OGP meetings:

In places where good satellite imagery isn’t available, a GPS tracker goes a long way. [OpenStreetMap offers a good comparison of GPS units](http://wiki.openstreetmap.org/wiki/GPS_Reviews). Whichever device you use, the basics are the same — you track an area by driving or walking around and later load the data into JOSM, where you can clean it up, classify it, and upload it into OpenStreetMap.

For our survey in Brasilia, we used [walking papers](http://walking-papers.org/), which are simple printouts of OpenStreetMap that let you jot down notes on paper. This is a great tool for on-the-ground surveys to gather street names and points of interest. It’s as simple as you’d imagine. You walk or drive around a neighborhood and write up information that you see that’s missing in OpenStreetMap. Check out our [report of our efforts doing this in Brasilia on our blog](http://mapbox.com/blog/surveying-brasilia/).

![](http://farm8.staticflickr.com/7274/6958489464_ef61741d7b.jpg)

Walking papers for Brasilia.

Further reading

For more details on how to contribute to OpenStreetMap, check out [Learn OSM](http://learnosm.org/) — it’s a great resource with step-by-step guides for the most common OpenStreetMap tasks. Also feel free to send us questions directly via [@mapbox](https://twitter.com/#!/mapbox).